Micromechanical yaw rate sensors are used in the automobile sector, e.g. in ESP systems, for rollover sensing or for navigation purposes. The object of the yaw rate sensor is the correct measurement of the vehicle movement about an axis of rotation.
DE 10 2009 027 897 A1 discloses a micromechanical yaw rate sensor with a disk-shaped rotationally oscillating mass, which extends in the x-y plane defined by a chip substrate and which is caused to make a rotational oscillation about an axis of rotation perpendicular to said plane (z axis). The rotationally oscillating mass is connected via four springs to a hub. The springs are arranged in a circular central cut-out of the rotationally oscillating mass, into which the hub projects. The end of the hub that is directed counter to the rotationally oscillating mass is fixedly arranged on the substrate.
If, during a rotational movement of the oscillating body about the axis of oscillation, the yaw rate sensor experiences a rotation about a sensitive axis (e.g. x axis) of the yaw rate sensor, then Coriolis forces act on the axis of oscillation, which effect tilting of the oscillating body with respect to a surface of the substrate. The tilting of the rotationally oscillating mass can be detected capacitively with the aid of measuring electrodes and can be evaluated.
For reliable detection of the yaw rate, it is desirable with a low overall height to decouple the rotational oscillation transmitted to the rotationally oscillating mass by an oscillating drive from the tilting brought about by the Coriolis forces to the furthest possible extent.